In the red corner, weighing in at 6.2 liters of displacement, we have GM’s new 6.2 liter V8 (L86). The naturally-breathing engine makes 420 horsepower and 450 lb-ft of torque in the all-new 2014 Silverado and 2014 Sierra, using the trusted small-block push-rod setup, but with a few modern technologies, including Variable Valve Timing, Cylinder Deactivation (or Active Fuel Management/AFM), and Direct Injection.

In the blue corner, weighing in at 3.6 liters of displacement, we have another new GM engine: a twin-turbocharged 3.6 liter V6 (LF3). The boosted six-banger also makes 420 horsepower, but 430 lb-ft of torque in the all-new 2014 Cadillac CTS. The engine is as power-dense as they get (116 horsepower per liter), representing the state-of-the art in powerplant engineering and design, through and through.

As you may have expected, both engines take entirely different approaches to optimizing the modern internal combustion engine, but put out the same amount of power and sport similar torque figures. As it stands, The General can pick and choose the best engine for the appropriate application — using the big and burly V8 for trucks, and the smaller, boosted six-pot for sports cars.

Feast your eyes on the similarities, and on the differences: (Chart on link)

GM isn't the only manufacturer with AFM. Fiat uses it on all their V8s if I'm not mistaken and even Honda uses it on their V6s.

The issue with AFM isn't cutting the cylinders off it's isolating the engine so you can't feel it. One of the biggest issues is the exhaust. As the engine shakes more in 4 cylinder mode, so does the exhaust and if it isn't isolated you can feel it.

You can barely feel it in the FS Pickups and SUVs. But go look at the Camaro exhaust. I think in 2011 they added one more flex coupling for a total of 4 I believe to try and better isolate the exhaust.

It's very tough to do when the exhaust is hanging off the body. The trucks have everything attached to the frame with one more level of isolation through the body mounts.

GM isn't the only manufacturer with AFM. Fiat uses it on all their V8s if I'm not mistaken and even Honda uses it on their V6s.

The issue with AFM isn't cutting the cylinders off it's isolating the engine so you can't feel it. One of the biggest issues is the exhaust. As the engine shakes more in 4 cylinder mode, so does the exhaust and if it isn't isolated you can feel it.

You can barely feel it in the FS Pickups and SUVs. But go look at the Camaro exhaust. I think in 2011 they added one more flex coupling for a total of 4 I believe to try and better isolate the exhaust.

It's very tough to do when the exhaust is hanging off the body. The trucks have everything attached to the frame with one more level of isolation through the body mounts.

I don't believe the 6.4 in the SRT8s has cylinder de-activation.

Another part of AFM that I think affects truck owners less than Camaro owners (and in particular, Camaro owners on this website) is aftermarket exhausts. I'm sure GM does what they can to eliminate the unpleasantness of the 3.1L V4 sound through careful exhaust tuning. But if you replace the muffler with one that isn't trying to minimize some of the bad frequencies (and instead might amplify a few of them), its not going to be a fun experience.

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Note, if I've gotten any facts wrong in the above, just ignore any points I made with them
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Originally Posted by FbodFather

My sister's dentist's brother's cousin's housekeeper's dog-breeder's nephew sells coffee filters to the company that provides coffee to General Motors......

GM isn't the only manufacturer with AFM. Fiat uses it on all their V8s if I'm not mistaken and even Honda uses it on their V6s.

The issue with AFM isn't cutting the cylinders off it's isolating the engine so you can't feel it. One of the biggest issues is the exhaust. As the engine shakes more in 4 cylinder mode, so does the exhaust and if it isn't isolated you can feel it.

You can barely feel it in the FS Pickups and SUVs. But go look at the Camaro exhaust. I think in 2011 they added one more flex coupling for a total of 4 I believe to try and better isolate the exhaust.

It's very tough to do when the exhaust is hanging off the body. The trucks have everything attached to the frame with one more level of isolation through the body mounts.

Actually CHRSLER'S V8s do. 1 Chrysler is not 100% owned by Fiat, 2 the engines and a lot of the tech is different enough throguh Fiats different companies (Maserati, Ferarri, Fiat, lancia, Alfa Romeo) differes enoguh that even if they did it is important to mention which umbrella the engine you are speaking of falls under.

Quote:

Originally Posted by DGthe3

I don't believe the 6.4 in the SRT8s has cylinder de-activation.

Another part of AFM that I think affects truck owners less than Camaro owners (and in particular, Camaro owners on this website) is aftermarket exhausts. I'm sure GM does what they can to eliminate the unpleasantness of the 3.1L V4 sound through careful exhaust tuning. But if you replace the muffler with one that isn't trying to minimize some of the bad frequencies (and instead might amplify a few of them), its not going to be a fun experience.

The 6.4 on automatic SRTs do, on manuals they do not. Same with the 5.7.

Actually CHRSLER'S V8s do. 1 Chrysler is not 100% owned by Fiat, 2 the engines and a lot of the tech is different enough throguh Fiats different companies (Maserati, Ferarri, Fiat, lancia, Alfa Romeo) differes enoguh that even if they did it is important to mention which umbrella the engine you are speaking of falls under.

The 6.4 on automatic SRTs do, on manuals they do not. Same with the 5.7.

Sorry majority owned makes them Fiat. JMO. Will you guys buy it in 6 months when they own 100%? They are controlled by Fiat plane and simple.

It was really close to being GM if the government had their way but that didn't happen so Fiat basically took the 2 billion they got from GM and got a controlling stake in Chrysler.

GM isn't the only manufacturer with AFM. Fiat uses it on all their V8s if I'm not mistaken and even Honda uses it on their V6s.

The issue with AFM isn't cutting the cylinders off it's isolating the engine so you can't feel it. One of the biggest issues is the exhaust. As the engine shakes more in 4 cylinder mode, so does the exhaust and if it isn't isolated you can feel it.

You can barely feel it in the FS Pickups and SUVs. But go look at the Camaro exhaust. I think in 2011 they added one more flex coupling for a total of 4 I believe to try and better isolate the exhaust.

It's very tough to do when the exhaust is hanging off the body. The trucks have everything attached to the frame with one more level of isolation through the body mounts.

Audi uses it on their V8 as well (at least on the S6 I've been looking at)...

I'd say that overall height wise the two will be fairly similar, the V6 might even be a tad taller. The V8 will obviously be longer (1 more cylinder per bank with bigger bore spacing) and probably a touch wider (the heads on an OHV don't stick out as far as OHC heads do, but the V8 would also have a taller deck sticking out at 45 degrees from vertical rather than just 30 off.

__________________

Note, if I've gotten any facts wrong in the above, just ignore any points I made with them
__________________
Originally Posted by FbodFather

My sister's dentist's brother's cousin's housekeeper's dog-breeder's nephew sells coffee filters to the company that provides coffee to General Motors......